Apparatus for making grids for secondary-battery plates.



PATBNTED APR. 12, 1904.

3 SHEETS-SHEET 1.

mvantoz A F. MADDEN'. APPARATUS FOR MAKING -GRIDS FOR SECONDARY BATTERYPLATES.

v APPLIOATION FILED APB. 11. 1903.

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PATENTED APR. 12, 1904.

A. P. MADDEN.

GRIDS POR SECONDARY BATTE APPARATUS `PoR MAKING RY PLATES.

APPLICATION FILED APR. 11. 1903.

3 SHEETS-SHEET 2.

N0 MODEL;

weones PAIENTIEID APR. 12, 190.4.

' A. P. MADDEN. APPARATUS PoR MAKING GRIDs PoR s200 APPLICATION FILEDAPR. 11

I0 MODEL.

NDARY BATTERY PLATES.

l UNITED STAT-Es Patented pril I2, 1904.

PATENT OFFICE.

ALBERT F. MADDEN, OF NEWARK, NEW JERSEY, A-SSIGNOR, BY MESNEASSIGNMENTS, TO THE ELECTRIC STORAGE BATTERY CO., OF PHILA- DELPHIA,PENNSYLVANIA, (A CORPORATION OFNEW JERSEY.`

APPARATUS FOR MAKING GRIDS FOR SECONDARY-BATTERY PLATES..`

SPECIFICATION forming part of Letters Patent No. 757,210, dated AprilI2, 1904.

Application filed Alpril. 11, 1903- To all/whom it may concern:

Be it known that I, ALBERT F. MADDEN, a citizen of the United States,residing at Newark, in the county of Esse'x and State of New Jersey,have invent'ed certain new and useful Improvements in Apparatus lforMaking Grids for Secondary-Battery Plates, of which the following is aspecification.

My invention relates to certain new and useful improvements in machinesfor making (preferably from lead or a suitable alloy) grids such as areused to form or constitute part of the electrodes of secondary batteriesor accumulators. It is important that such grids be vmade with Ias greatas possible an expanse of surface and as complete as possibleramifications of the conducting material to all parts of the grid inorder that a wide area of grid be exposed to the action of theforming-current or to the application of the active material and thatthe current 'may be conducted to and from all parts of the surface. Ihave had in view the production of a battery plate or grid having analmost infinite subdivision of the material by shelves and apertures;and. the object of my invention is an apparatus designed to produce sucha grid. Such apparatus comprises composite dies with suitablecompressing uappliances for placing the dies in proper` relation to formthe grids o1' conductors from sheets or slabs of suitable material andmeans for ejecting or freeing the grids from the die after they havebeen properly formed.

Heretofore in grid-forming apparatus many ldiiculties have beenencountered in providing meansfor removing the grid from thedie after.it has been` molded, cast, or othenwise formed'. .Owing to the delicateformation of secondary-battery grids, great care must necessarily beexercised in removing the-grid from the die in order not to break orcrack the thin partitions or distort or twist the grid, so.

as to render it value ess after removaLj Mechanicalmeans for. removingthe grids have proven ineffectual owing to the unequaledhering tendencyofy the grid to the mold or die and the locationaldistribution of theejectlng power on the grid.

'senti No. 152,155. ma modem y In my improved method. hereinafterspecifi-cally described. but now generally referred to, I construct theforming-die of an alternate series ofmetal plates of differentthicknesses suitably channeled transversely and longitudinally andprovided with interstices for the admission of the metal in forming-thoIgrid. After the grid has been formed it is necessary to exert Vsomeforce to remove it from its seated position in the die. To accomplishthis, I use fluid as an ejecting element and carry it into the die byprojecting a pipe transversely through the platescomposing the die andforcing thefluid therethrough into the channels 'and interstices of thedie and directly against the entire under surface ofthe grid. Whenhuid-pressure is exerted against the grid, it will be readily releasedfrom the die and follow the upward movement of the upper die untilwholly disengaged from the formingdie, whereupon the fluid-pressure willcease and the normal condition and relation of the dies will be resumed.

My present invention comprehends certain ,novel combinations andorganizations of instrumentalities hereinafter more4 fully described andthen specifically designated in the claims. V

In the drawings, Figure 1 is a plan view of the lower or grid-formingdie. longitudinal vertical section on the line A A, Fig. 1. Fig. 3 is atransverse vertical section Fig. 2 is a .of the die on a line throughthe liquid-su pply pipe. Fig. I is an elevation of the upper and lowerdies in position to be operated. Fig. 5 is an enlarged detail of aportion of the lowerdie face. Fig. 6is an enlarged perspective de- 'tailof a portion of the lower die. Fig. 'I1' is a perspective detail sideview of a portion-of one of the die-plates. Fig. 8 is a modified form.In the construction and practical appllcation of the apparatus anysuitable -means may "be employed to operatively control the opposingdies. The lower die-is indicated at l and tutesY a most important partof the present invIO , per plates are of the same length, but ofdifformer patented apparatus' inthat the grid is formed wholly by theunder die and a Huid element used as a means forejecting or releasingthe grid'from the die instead of mechan# ical means or appliances, thusinsuring the 're= moval of the grid with comparative ease Withoutbuckling or cutting or otherwise injuring it.' To produce a batteryplate or` grid that will have the largest possible area of homogeneousconductive surface in most intimate contactual relations with allportions of the active material and with the electrolyte, is mostdesirable.

The lower die is preferably composed of alternating series of steel bars10 and plates 9, of any suitable material-such as copper, mica, or thelikearranged side by side and securely bound together in the desiredposition between said bars 10. The steel bars and copferentdepths, thesteel bars also being thicker than the copper plates and constitute themain body of the die upon which the grid is formed.

VThe steel bars are provided with transverse' holes 12, that registerwith similar holes 13 in the copperplates and through which tie-bolts 14pass and are engaged by nuts 15 on the outer sides of the side bars 10,securely binding together in its entirety the parts composing the lowerdie. When the die is assembled, as shown in Figs. 1 and 3, a depression16 oc- .curs in the face of the die that is of the same configuration asthe blank plate to be operated upon to form the grid. These two facialplanes of the under die are engaged by corresponding inverse planes onthe upper die.

` Transverse Vertical channels 18 of suitable depth and terminatingagainst the s ide lbars 10 are cut in the upper sides 'of the steelbars, into which the metal of the blank grid is forced and into whichfluid is admitted to eject the grid, as will hereinafter be more fullyexplained. By employing copper or other soft-metal plates between thesteel bars it becomes possible to make the die non-leakable when thefluid is admitted to the channels and interstices to eject the grid.Arranged longitudinally along the 'steel bars between the'transversechannels 18 are'vertical interstices 20, which are adaptedV to formprojecf tions on the grid to assist in retaining the active matter onthe grid. Imposed 'between the steel bars are copper or other suitablesoftmetal plates 9, that are cut away, as shown-at 22, to form'longitudinal channels 23 betweenthe steel bars. The extreme ends of thecopper plates, Ias .shown in Fig. 6, extend upwardly to the highestfacial plane of the die.l in orderg-to present an unbroken surfacearound the depression 16.` The opposing dies are here termed upper andlower dies for the .purpose'of distinguishing them; 4but itl suitableheating appliances.

should be understood that they can be ar- 65 ranged in oppositerelation, if desired. l

Extending transversely through openings 24, 25., and 26 in the sidebars, steel bars, and' copper plates is a pipe 27, which is adapted toposite end of the pipe 27 is threaded a nut 33,

vWhich-engages the side bars 10 to retain the supply-pipe in its properposition, as shown in Fig. 3. The fluid-supply pipe 27 has a number ofradial springs 35 in the top thereof through which the fluid ows into agroove or channel 36, which is formed by notches 37, cut in the steelbars above thel supply-pipe 2.7.

By referring to Figs. 2 and 6 it'will be noticed that the copper platesare cutaway, as shown at 38, in order to permit the iuid to enter thechannels 23 between 'the steel bars. Thus it will be seen thatwhen thefluid is placed u nder pressure it will iow through the openingsgitudinal and transverse channels and also into the interstices in thesteel bars and be equally distributed against the under surface of thegrid for the purpose of ejectment.

The frame of the grid is 'formed by having a marginal depression 4()V inthe body of the lower die of greater depth than the depression 16 andhaving the outer wall or shoulder 40', surrounding the vsaid depression40, cor.- responding with the marginal form of' both the blank and thefinished grid, as shown in Fig. 1. i

' lThe upper dieis slidably mounted on stanv35 into the channel 36 andthence into the lon'- IOO chions '3-and any suitable vmeans employed tov operatively control its .action with relation .to the underdie; lbutinasmuch as such mechanism forms no part of my present invention it' hasnot been illustrated.u The upper die is provided with horizontalheat-chambers 45 of any suitable cross-section, into which heat is IIO vintroduced either by Bunsen burner o'r other f The upper die is allowedto assumea temperature just suicient to cause the blank plate when thedie engagesA it to assume a comparativelysoft and plastic p cond' ion,thereby permitting the metal to be equa ly forced or distributed intothe channels and interstices of the lower die, assuring compression ofthe entire grid or plate to practically a perfect uniform homogeneitythroughoutits whole structure. The face 48,0f the upperdieengages theface 49ofthe lower die, and the marginal rib 50 of the upper die entersthe depression 40 in the`l'owerdie and assists in forming the 'frame-ofthe plate or "grid. Themarginal rib 5,0 is. not ofvsuiiicient depth toreach the bottom of the depression 40, and the difference between thetwo planes will be the thickness of the grid or plate after the opposingdies have operated on the blank plate to properly form 4the grid.

A thin film or fin of' metal may be left on the top of the grid afterformatiomwhich materially assists in the ejecting ofthe grid from thedie. through the channels and interstices in the die, it will flow underthe lms or fins and having more surface presented for the iiuid toengage will be more quickly and readily ejected. After the grid isremoved from the die the lms or fins can be' removed in any suitablemanner without impairing its value. Of course it is obvious that anyform of grid construction can be employed, the thickness,

configuration, and design being matters of choice, the blanks consistingof sheet-lead or its equivalent, either perforate or intact.

In Fig. 8 a modied form of the invention is shown, wherein a grid,having been properly formed, is allowed to remain in the channels-andinterstices of `the lower die, so that when a blank plate is placed uponthe lower die to be formed it will upon the operation of theopposing'die be driven into the channels and interstices and in Acontactwith the first grid. The uid under pressure will force the under gridupward, carrying with it the newlyformed grid, until it is ejected fromthe die, whereupon the fluid-pressure will cease and the lower gridremain in the Idie for asimilar subsequent operation. The mainl objectof this modified form is to have the channels and interstices lled bymetallic matter-to morecompletely hold the ejecting iiuid in subjection.

The operation of my invention is as follows: A sheet yor blank of leadpreviously rolled or molded and about one-eighth of an inch Ainthickness-and having the desired marginal contour is placed on the die1, and the upper or opposing die 2 is by suitable means forced intoengagement with the metal blank on the lower die. The upper die isheated to a temperature suiicient to maintainl a plastic but not moltencondition of the metal blank, which will cause the metal of the blank tomore readily enter the longitudinal and transverse channels andintersticesin the lower die when the desired limit of pressure isexerted on said upper die. When the upper die has descended the limit ofits movement, the metal of the blank will be equally distributed in thechannels and interstices of the lower die, and the marginal frame of thegrid will be formed in the depression l40 in the lower die by themarginal rib 50 on the opposing die. now being formed, the upper diestarts torecede to its initial position, and the ejecting" fluid, whichpervades all the channels and interstices in the lower die, is placedunder pressure, which will cause it to rise in the When the fluid isforced upwardchannels and interstices and be equally distributedagainstthe entire under surface of the grid. While the upper dieis being slowlywithdrawn from `engagement with the lower die the pressure of the uidwill cause the grid to follow the retreating upper die until said gridhas been ejected from the channels and interstices of the lower die,after which the Huid-pressure will cease and the Huid allowed to recedeto its initial condition preparatory to a subsequent operation.

By organizing and operating the dies in the manner herein setforth andutilizing fluid as an element for ejecting the grids after they areformed enables me to make a battery grid or plate having very delicatestructure giving maxlmum conductivitywith minimum weight.

Furthermore, all parts of the grid or plate are homogeneouslyc0mpressed,thus giving practically'uniform conductivity throughout theentire electrode either for the Plante .method or to all parts offilling material which maybe used in the latticed openings and betweenvthe multingered projections of the grid or plate. Physical andmechanical imperfections, 4marginal disintegration, distortion of -thegrid when ejected, and `other undesirable features of grid-forming areentirely-eradicated in the presentvmethod of forming and 4ejecting' thegrid.

' Having thus described my invention, the following swhat I claim as newtherein and desire to secure by Letters Patent:

1. In apparatus of the character described, a grid-forming die providedwith channels and interstices in which the grid is formed and meansthrough which Huid is admitted to said channels and interstices to ejectthe grid from the die.

v2. In apparatusof the characterdesoribed, a composite grid-forming dieconstructed of immovable parts', and provided with channels andinterstices projecting .below the facial .plane of the die for thereception of the gridforming metal, and means for supplying uid to thechannels and interstices of the die for the purpose of ejecting the gridafter it has been formed. Y

3. In apparatus of the character described,

`a plurality of hard-metal bars having interstices and channels cuttherein, a plurality of soft-metal plates interjacent and contiguous tothe metal bars adapted to form channels IOO IIO

between said bars, and means for conveying fluid to the channels andinterstices of the assembled die, for the purpose explained.

4. In apparatus of the character described,

Aa grid-forming die composed of alternate series of steel bars providedwith transverse channels and interstices and soft-metal plates arrangedto form longitudinal channels, means for binding the bars and platestogether, and means for admitting uid to the channels and interstices,for the purpose explained.

. 5. Inpapparatus of the character described,

a die Whose component grid-forming elements are a series of hard-metalbars, provided with channels'and interstices' projecting )below thefacial plane of the die, and a series of softmetal plates arranged inalternate relation with the said bars and cut away below the 'facialplane yof the die to form longitudinal channels, means for securing thebars and plates in contiguous relation, and a pipe forming part of theassembled die and provided i@ with openings for admitting fluid into thechannels and interstices, for the purpose explained.

ALBERT Ea MADDENa Witnesses:

J. GREEN, WM. A. COURTLAND.

